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CVE.org (no NVD analysis yet)· CNA GitHub_M

CVE-2026-55453: CUPS ipp backend status-line injection can update queue PPD and lead to conditional RCE as lp via foomatic-rip

Noroxi assessment

Priority: Monitor (action score 13/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.19% (FIRST EPSS).
  • Someone with local access to the system can trigger it. No account or password is required. A user must open a link or visit a page. No special conditions are required; it is repeatable.
  • Fixed version: OpenPrinting cups 2.4.20; azl3 cups 2.4.19-1 on Azure Linux 3.0 Release Notes; azl3 cups 2.4.19-2 on Azure Linux 3.0 Release Notes.

Low priority for now. Upgrade to OpenPrinting cups 2.4.20; azl3 cups 2.4.19-1 on Azure Linux 3.0 Release Notes; azl3 cups 2.4.19-2 on Azure Linux 3.0 Release Notes or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

OpenPrinting CUPS is an open source printing system for Linux and other Unix-like operating systems. Prior to 2.4.20, the backend/ipp.c quote_string() function preserves carriage-return and line-feed characters in a remote printer-controlled marker-message before report_attr() writes the value to the scheduler status stream. The scheduler can parse an injected newline as a separate PPD: control line and persist an attacker-selected PPD keyword. The reporter demonstrated that a later print job on a Foomatic-backed queue could consume an injected FoomaticRIPCommandLine value and execute in the filter context as lp. This issue is fixed in version 2.4.20.

LowCVSS 3.3 · v3.1—No exploit Fix available
Published
Oct 15, 2026
Updated
Oct 20, 2026
EPSS
0.1% · 9th percentile

Report tools

JSON

Action score

13

Monitor

Low priority for now.

CVSS
13 / 40 · 3.3 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · GitHub_M
3.3
NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-55453

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
openprintingcups

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • openprinting cupsbefore 2.4.20

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • OpenPrinting cups

    • < 2.4.20affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12cupsfrom 0—
openSUSE:Tumbleweedcupsbefore 2.4.20-1.12.4.20-1.1
Red Hat:hummingbird:1cupsbefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1
Red Hat:hummingbird:1cups-clientbefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1
Red Hat:hummingbird:1cups-develbefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1
Red Hat:hummingbird:1cups-filesystembefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1
Red Hat:hummingbird:1cups-ipptoolbefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1
Red Hat:hummingbird:1cups-libsbefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1
Red Hat:hummingbird:1cups-lpdbefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1
Red Hat:hummingbird:1cups-printerappbefore 0:2.4.19-4.6.hum10:2.4.19-4.6.hum1

Same product

openprinting: all records

Other highest-scoring records for the same primary product.

  • CVE-2025-58060cups has Authentication bypass with AuthType Negotiate
    32Monitor
  • CVE-2023-4504OpenPrinting CUPS/libppd Postscript Parsing Heap Overflow
    28Monitor
  • CVE-2023-34241CUPS vulnerable to use-after-free in cupsdAcceptClient()
    28Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-107888Oct 9, 2026 · OpenPrinting CUPS before 2.4.20 contains a NULL pointer dereference in cupsdCheckJobs() when a job marked job-held-on-create refers to a tem
    22Monitor
  • ← EarlierCVE-2026-107890Oct 9, 2026 · OpenPrinting CUPS before 2.4.20 contains a NULL pointer dereference caused by repeated IPP group tags in job-creation requests.
    22Monitor
  • Later →CVE-2026-55467Oct 15, 2026 · CUPS fax option values bypass the CVE-2026-34980 control-character sanitizer (incomplete fix)
    10Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
OpenPrinting cups2.4.20 · descriptionVendor (CNA)
azl3 cups 2.4.19-1 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
azl3 cups 2.4.19-2 on Azure Linux 3.0Release NotesMicrosoft (MSRC)
opensuse:cups2.4.20-1.1 · openSUSE:TumbleweedPackage registry (OSV)
red hat:cups0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:cups-client0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:cups-devel0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:cups-filesystem0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:cups-ipptool0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:cups-libs0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:cups-lpd0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)
red hat:cups-printerapp0:2.4.19-4.6.hum1 · Red Hat:hummingbird:1Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. Fix recordedsame day
  3. TodayNov 5, 2026+21 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • No account or password is required.
  • A user must open a link or visit a page.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
none
Integrity
none
Availability
low · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
None
User interaction
Required
Scope
Unchanged
Confidentiality impact
None
Integrity impact
None
Availability impact
Low

Weakness class (CWE)

CWE-74 · Improper Neutralization of Special Elements in Output Used by a Downstream Component ('Injection')

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Change log

  1. SSVC exploitation— → none
  2. Exploit maturity— → none
  3. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records